The detection of contraband and explosives in vehicles is of paramount importance, not only to the military, but to society in general. As new detection methods emerge, smugglers continue to find new and more creative places to establish hiding places in vehicles; these hiding places are, by design, not easily accessed for inspection. One example of such a hiding place is to establish a void in a vehicle's fuel tank. Absent specialized equipment, it would be very difficult to search the fuel tank of each vehicle for special voids.
Additionally, it should be appreciated that, when deciding how thoroughly vehicles should be searched, operational security considerations must be balanced with the inconvenience of such a thorough search. In times of extremely high threat conditions, it may be feasible to search all vehicles thoroughly. But for other, lesser threat levels, it may not be feasible to search tanks and compartments of each and every vehicle passing through a checkpoint, because it takes too long to accomplish that search.
On the one hand, vehicles can be x-rayed. However, x-ray machines are extremely expensive, few in numbers, time consuming, and quite inconvenient. Dogs can be used to sniff out contraband, but they are of limited use and smugglers are finding ways to defeat this method of detection. Neutron beam detectors have been used, but because of safety issues, operators prefer not to use these devices.
In view of the above, what is desired is a system and method for searching voids and compartments of vehicles that is non-invasive, that can be quickly accomplished at a checkpoint having a high throughput of vehicles, and that is safe for the operator and relatively easy to use.